The disclosed embodiments generally relate to calibration processes and more particularly to verifying irradiance and radiance characteristics of a sensor.
Previously developed laser based facilities for spectral irradiance and radiance responsivity calibrations typically use a number of sources for calibrating instruments or sensors directly in irradiance or radiance mode. Generally, the emission from high-power, tunable lasers is introduced into an integrating sphere using optical fibers, producing uniform, quasi-Lambertian, high-radiant-flux sources. Reference standard irradiance detectors, calibrated directly against national primary standards for spectral power responsivity and aperture area measurement, are used to determine the irradiance at a reference plane. The source radiance may also be readily determined using the measurement geometry. The facilities typically use multiple lasers, in some cases, dye lasers, to cover a spectral region from 415-700 nm, and Ti:sapphire lasers to cover the spectral range from 350-500 nm with frequency doubling, and from 680-1050 nm.
It would be advantageous to provide an apparatus and method to perform irradiance and radiance responsivity calibrations that uses a tunable laser system to overcome these and other disadvantages.